1. Field of the Invention
The present invention relates to an automatic garage door opener for raising and lower a garage door relative to a garage door opening a in a vehicle entry wall of a garage.
2. Description of the Prior Art
Various types of automatic garage door openers have existed for many years. Conventional automatic garage door openers are electromechanical devices which raise and lower a garage door to unblock and block a garage door opening in response to actuating signals. The signals are electrical signals transmitted by closure of a push-button switch through electrical wires or by radio frequency from a battery-operated, remote controlled actuating unit. In either case the electrical signals initiate movement of the garage door from the opposite condition in which it resides. That is, if the garage door is open, the actuating signal closes it. Alternatively, when the garage door is closed, the actuating signal will open the garage door. Once movement has been initiated, the system is deactuated when the garage door movement trips a limit switch as the garage door approaches its open or closed position.
The drive systems for conventional automatic garage door openers are frequently rather large and cumbersome and are difficult for a single individual to install. Conventional drive systems typically include either a very long worm drive or a very long drive through a chain loop tensioned between a pair of sprockets. The chain is connected to the garage door. A typical worm drive shaft is at least about eight feet in length, while the sprockets in a chain loop drive are likewise separated by a distance of at least eight feet. The large distances involved from one end of the drive system to the other makes conventional automatic garage door openers quite difficult for one person to install.
A further disadvantage of conventional automatic garage door opening systems is that they are designed for permanent installation. That is, once the automatic garage door opening system has been installed, it cannot be easily taken down, transported to a new location, and reinstalled. As a consequence, people who rent garages are highly unlikely to purchase a conventional automatic garage door opener since they are fully aware that they will, in all likelihood not be able to take the automatic garage door opener with them should they choose to relocate.
A further disadvantage of conventional garage door opening systems is that they typically extend down into the interior of the garage at least about six inches. As a consequence, they cannot be installed in garages having low overhead clearances since they extend downwardly a distance sufficient to create an overhead obstruction. On the other hand, where a garage has a particularly high ceiling, conventional garage door openers cannot be utilized without first creating a support framework that extends downwardly into the interior of the garage to provide a mounting base for a conventional worm drive or chain loop drive system.